The role of surface spin polarization on ceria-supported Pt nanoparticles

Abstract

In this work, we employ first-principles simulations to investigate the spin polarization of CeO 2 -(111) surface and its impact on interactions between a ceria support and Pt nanoparticles. For the first time, we report that the CeO 2 -( 111) surface exhibits a robust surface spin polarization due to the internal charge transfer between atomic Ce and O layers. In turn, it can lower the surface oxygen vacancy formation energy and enhance the oxide reducibility. We show that the inclusion of spin polarization can therefore significantly reduce the major activation barrier in the proposed reaction pathway of CO oxidation on ceria-supported Pt nanoparticles. For metal-support interactions, surface spin polarization enhances the bonding between Pt nanoparticle and ceria surface oxygen, while CO adsorption on Pt nanoparticles weakens the interfacial interaction regardless of spin polarization.